Dr. Pankaj N. Maheshwari


Understanding Urinary Stone Disease

ajan, a 60-year-old banker has seen it all. He has lived with and suffered due to urinary stones from his college days for over 35 years.

At the age of about 20 years he was found to have a large stone in his left kidney. The only facility he had that time was to get it removed surgically. A large cut was made in his flank to remove the 3 cm stone. He spent over 10 days in hospital and was out of college for nearly six weeks. Sadly, one small stone fragment was left behind during the open surgery. Open surgeries carry this risk as they are not done under X-ray control.

Luckily for him, shock wave lithotripsy (SWL) had just started in India at that time. He underwent two sessions of SWL and found the treatment to be easier and effective. Without anesthesia, without any cut, nearly pain-free fragmentation of the stone was performed externally and he passed out the fragments in his urine. He was very happy.
Eight years later, Rajan was diagnosed stones in both his kidneys. The one on right was blocking his ureter (tube joining the kidney to the urinary bladder). He was treated by ureteroscopy surgery (URS). A fine endoscope was inserted up the ureter and the stone was fragmented and removed. Again this needed just one-day hospitalization and was very comfortable.
Left side had formed a 28 mm calculus hence Rajan was advised percutaneous nephrolithotomy (PCNL) surgery. When Rajan first heard about the surgery, he questioned how it would go. It involved making a small tract in his back, and inserting scopes through it to reach the stone. The stone would be fragmented and removed through this tract. Later, he said he was amazed at how smoothly the stones were removed. He felt sad that he had needed the open procedure the first time he had formed a stone during his college days.
Rajan is now very careful about what he eats and drinks.He wishes he had known all along about how much your diet and fluids affect the way stones form. “I am much better educated today about how to prevent kidney stones,” says Rajan.“I drink a lot of fluids and eat less salt and foods that form my type of stones.If I had some general education about stones before, I would not have needed the procedures and surgeries that I’ve had.” Rajan hopes his story will help millions of people diagnosed with kidney stones each year.

What are Kidney Stones?

Urinecontains many dissolved minerals and salts.When your urine has high levels of these minerals and salts, crystals can aggregate and stones can form.Kidney stones can start small but can grow larger in size.They can even fill the inner hollow structures of the kidney.Some stones stay in the kidney, and don’t cause problems.Others can travel down the ureter (the tube between the kidney and the bladder). Small stones that reach the bladder, can be passed out through urine.If the stone becomes lodged in the ureter, it blocks the urine flow.This causes great pain.

How do the Kidneys and Urinary System Work?

The kidneys are fist-size organs that handle the body’s fluid and chemical levels. Most people have two kidneys. Each one sits on each side of the spine behind the liver, stomach, pancreas and intestines.The kidneys, ureters and bladder are part of your urinary tract.The urinary tract makes, transports, and stores urine in the body. The kidneys’ main job is to clean water-soluble waste from the blood.The waste becomes urine, which travels down the ureters into the bladder for storage. Urine leaves your body through the urethra.Healthy kidneys also control the levels of sodium, potassium and calcium in the blood. Kidney stones form in the kidney, and sometimes move into the ureter.The ureters are tubes leading from the kidneys to the bladder.If a stone leaves the kidney and gets stuck in the ureter, it is called a ureteral stone.
Common symptoms of kidney stones are:
    • A sharp, cramping pain in the back,flank and side.The pain often moves to the lower abdomen or groin.Some women say the pain is worse than childbirth labor pains (so this is the most severe pain a man will go through!!).The pain can start quickly and come in episodes.It can come and go as the body tries to get rid of the stone. Pain may be associated with nausea vomiting or fever.
    • A feeling of intense need to urinate.
    • Going to the bathroom more often or having a burning feeling when you go.
    • Urine that is dark or red due to blood.Or sometimes urine has red blood cells that can’t be seen with the naked eye.
    • Nausea and vomiting.

    • Men may feel pain at the tip of their penis

What are Kidney Stones Made of?

Kidney stones come in many different types and colors. How you treat them and stop new ones from forming depends on the type of stone you have.
Calcium stones are the most common type.There are two types of calcium stones: calcium oxalate and calcium phosphate.Calcium oxalate is more common.Some people have too much calcium in their urine, raising their risk.Even with normal amounts of calcium in the urine, calcium stones may form for other reasons.

Uric acid is a waste product that comes from chemical changes in the body. Uric acid crystals do not dissolve well in acidic urine. Instead it will form a uric acid stone.

Having acidic urine may come from:

  • Being overweight
  • Chronic diarrhea
  • Type 2 diabetes (high blood sugar)
  • Gout
  • A diet that is high in animal protein and low in fruits and vegetables

Struvite stones are common type of stone in Indian population. These stones are related to chronic urinary tract infections (UTIs). Some bacteria make the urine less acidic and more basic or alkaline. Magnesium ammonium phosphate (struvite) stones form in alkaline urine. These stones are often large, with branches, and they often grow very fast.

People who get chronic UTIs, such as those with long-term tubes in their kidneys or bladders, or people with poor bladder emptying due to neurologic disorders (paralysis, multiple sclerosis, and spina bifida) are at the highest risk for developing these stones. These can also happen in persons with uncontrolled diabetes.

What Causes Kidney Stones?

How are Kidney Stones Diagnosed?

The common presentation of stone is by flank pain associated with burning in urine, blood in urine, nausea or vomiting. “Silent” kidney stones can happen. They cause no symptoms and are often found on routine investigations.
Can stones be really silent? May be. More often we fail to recognize the trouble caused by the stone. If suppose you get back ache tomorrow, will you really think of stone as a cause of pain? We do not investigate the daily niggles and then think that the stone was silent.
The common presentation of stone is by flank pain associated with burning in urine, blood in urine, nausea or vomiting. “Silent” kidney stones can happen. They cause no symptoms and are often found on routine investigations.
When a person has blood in their urine (hematuria) or sudden abdominal or side pain, tests may be ordered.An ultrasound or a CT scan can clearly diagnose a stone.These imaging tests tell you doctor how big the stone is and where it is located.A CT scan is a single most important test that will give all the necessary information. It is used in emergency because it can make a quick and exact diagnosis.
A urinalysis is also done to learn whether or not you have a kidney infection.If your kidney stone(s) is in a difficult location, other imaging tests may be used.

Get Treated

Treatment of kidney stones depends on the following:
  • The type of stone

  • Location of the stone

  • How bad it is

  • Length of time you have had symptoms.
There are different treatments to choose from.It is important to talk to your doctor about what is best for you.  

Surgeries to remove stones in the kidneys or ureters are:


Shock Wave Lithotripsy (SWL) is used to treat stones in the kidney and ureter.Shock waves are focused on the stone using X-rays or ultrasound to pinpoint the stone.Repeated firing of shock waves on the stone usually causes the stone to break into small pieces.These smaller pieces pass out in the urine over a few weeks. SWL is indicated for calculi less than 15 mm in the kidney. This procedure does not work well on hard stones, such as cystine, some types of calcium oxalate and calcium phosphate stones, or very large stones. Because of possible discomfort caused by the shock waves and the need to control breathing during the procedure, some form of anesthesiamay be needed.

With SWL, you may go home the same day as the procedure.You may be able to resume normal activities in 2 to 3 days.You can use a strainer to collect the stone pieces as they pass.These pieces will be sent to a lab to be tested.

Although SWL is widely used and considered very safe, it can still cause side effects.You may have blood in your urine for a few days after treatment.Most stone pieces pass painlessly.Larger pieces may get stuck in the ureter, causing pain and the need for other removal procedures.


Ureteroscopy (URS)is used to treat stones in the kidney and ureter.URS involves passing a very small telescope, called an ureteroscope, into the bladder, up the ureter and into the kidney.Rigid telescopes are used for stones in the lower part of the ureter near the bladder.Flexible telescopes are used to treat stones in the upper ureter and kidney. Flexible ureteroscopy is also called RIRS (Retrograde Intrarenal surgery)

The ureteroscope lets the urologist see the stone without making an incision (cut).General anesthesia keeps you comfortable during the URS procedure.Once the urologist sees the stone with the ureteroscope, a small, basket-like device grabs smaller stones and removes them.If a stone is too large to remove in one piece, it can be broken into smaller pieces with a laser or other stone-breaking tools.

Once the stone has been removed in whole or in pieces, your doctor may place a temporary stentin the ureter.A stent is a tiny, rigid plastic tube that helps hold the ureter open so that urine can drain from the kidney into the bladder.Unlike a catheter, this tube is completely within the body.It does not require an external bag to collect urine.

You may go home the next day after the URS and can begin normal activities in 2 to 3 days.If your urologist places a stent, he or she will remove it 14 to 21 days later.It is very important to remember to remove the stent when your urologist tells you.Leaving the stent in for long periods can cause an infection and loss of kidney function.


Percutaneous Nephrolithotomy (PCNL)is the best treatment for large stones in the kidney.General anesthesia is needed to do a PCNL.PCNL involves making a small tract in the back, just large enough to allow a rigid telescope (nephroscope) to be passed into the kidney where the stone is located. An instrument passed through the nephroscope breaks up the stone and suctions out the pieces.The ability to suction pieces makes PCNL the best treatment choice for large stones.

After the PCNL, a tube may be left in the kidney to drain urine into a bag outside the body (nephrostomy bag).The tube is usually left in overnight or for a few days.You may have to stay in the hospital for 36-48 hours after this operation.

Your urologist may choose to do X-rays while you are still in the hospital to confirm stone clearance. You can begin normal activities after about 1 to 2 weeks.

Other Surgery

Other kidney surgery is rarely used to remove stones.Open, laparoscopic or robotic surgery may be used only if all other less invasive procedures fail.


Part of preventing stones is finding out why you get them. Your doctor will perform tests to find out what is causing your stones.After finding out why you get stones, your doctor will give you tips to help stop them from coming back.Some of the tests he or she may do are listed below.
Your doctor will ask questions about your personal and family medical history. He or she may ask:
  • Have you had more than one kidney stone before?

  • Has anyone in your family had stones?

  • Do you have a medical condition that may increase your chance of having stones, like frequent diarrhea, gout or diabetes?

Knowing your eating habits is also helpful.You may be eating foods that are known to raise the risk of stone.You may also be eating too few foods that protect against stones or not drinking enough fluids. Understanding your medical, family and dietary history helps your doctor find out how likely you are to form more stones.
After taking a complete history and doing a physical exam, your doctor may take blood and urine samples for testing.Blood tests can help find if a medical problem is causing your stones.Your urine can be tested to see if you have a urinary tract infection or crystals that are typical of different stone types.If you are at high risk for getting stones in the future, a 24-hour urine collection can be done.This test will reveal the levels of different stone-forming substances in your urine.The results of this test can help your doctor recommend specific diets and medications to prevent future stones.
When a doctor sees you for the first time and you have had stones before, he or she may want to see recent X-rays or order a new X-ray.They will do this to see if there are any stones in your urinary tract.Imaging tests may be repeated over time to check for stone growth.You may also need this test if you are having pain, hematuria (blood in your urine) or recurrent infections.
If you pass a stone or a stone is removed by surgery, your doctor will want to test it.Testing the stone will determine what type of stone it is.This information helps your doctor decide the best way to prevent future stones.
Once your doctor finds out why you are forming stones, he or she will give you tips on how to prevent them. This may include changing your diet and taking certain medications. There is no “one-size-fits-all” diet for preventing kidney stones. Everyone is different. Your diet may not be causing your stones to form. But there are dietary changes that you can make to stop stones from continuing to form.

Diet Tips To Prevent Stone

If you are not producing enough urine, your doctor will recommend you drink at least 3.5 liters of liquid each day.This equals about 15-18medium size glasses.This is a great way to lower your risk of forming new stones.Remember to drink more to replace fluids lost when you sweat from exercise or in hot weather.All fluids count toward your fluid intake.But it’s best to drink mostly no-calorie or low-calorie drinks.This may mean limiting sugar-sweetened or alcoholic drinks.

Knowing how much you drink during the day can help you understand how much you need to drink to produce 2.5 liters of urine.Use a household measuring cup to measure how much liquid you drink for a day or two.Drink from bottles or cans with the fluid volume on the label.Keep a log, and add up at the end of the day or 24-hour period.Use this total to be sure you are reaching your daily target urine amount of at least 2.5 liters of urine daily.

One simple way is to assure that you need to go to the loo minimum 7-8 times in 24 hours. Observe the color of the urine, it should be water colored always. Having a dilute urine is the most important precaution in reducing the risk of recurrence.
Indian food is salt rich. Excess salt in diet will increase the calcium in your urine. This tip is for people with high sodium intake and high urine calcium. Your doctor may advise you to avoid foods that have a lot of salt. The following foods are high in salt and should be eaten in moderation:
  • Papads, Aachars and chutneys

  • Extra table salt

  • Cheese (all types)

  • Most frozen foods and meats.

  • Canned soups and vegetables

  • Breads, rolls and baked goods

  • Salty snacks, like chips and pretzels

  • Bottled salad dressings and certain breakfast cereals

  • Pizza and lasagna

  • Canned and bottled sauces

  • Certain condiments, table salt and some spice blends

Eating at least 5 servings of fruits and vegetables daily is recommended for all people who form kidney stones. Eating fruits and vegetables give you potassium, fiber, magnesium, antioxidants, phytate and citrate, all of which may help keep stones from forming.

A serving means one piece of fruit or one potato or one cup of raw vegetables. For cooked vegetables, a serving is ½ cup. If you are worried you may not be eating the right amount of fruits and vegetables, talk to your doctor about what will be best for you.

Remember: foods with seeds in them DO NOT cause stones!!
If you make calcium oxalate stones and your urine uric acid is high, your doctor may tell you to eat less animal protein.

If your doctor thinks your diet is increasing your risk for stones, he or she will tell you to eat less meat, fish, seafood, poultry, pork, lamb, mutton and game meat than you eat now. This might mean eating fewer times during the week, or eating smaller portions when you do eat them. Having one vegetarian dish with animal protein is a good idea. The amount to limit depends on how much you eat now and how much your diet is affecting your uric acid levels.
Adequate amount of calcium in diet is very important. DO NOT stop calcium in diet, this will increase your risk of oxalate or phosphate calculi. In India where a major population is vegetarian, continue milk and milk products. If your doctor has advised calcium supplements, please take them as you may be low on your calcium levels. Talk with your doctor or dietitian about whether you need supplements. Eating calcium-rich foods or beverages with meals every day is a good habit.

Frequently asked questions

These stones get their name from the shape they take as they grow inside the kidney. Staghorn stones often form because of repeated urinary tract infections (UTIs) with certain bacteria. Even though they can grow to a large size, you may have no idea you have them. They cause little or no pain. A staghorn stone can lead to poor kidney function, even without blocking the flow of urine. Most often, staghorn shaped stones are the infection type of stone. They usually need removal as they carry a risk to your kidney.
Kidney stones are most common in people who have a family member with urinary stones. Some conditions that cause stones are inherited. But sometimes, kidney stones form simply because of the way we eat as a family. Similar habits, environment and lifestyles, can cause kidney stones among family members.
Yes, but rarely. Kidney stones can cause damage if they cause repeated or serious infections. Or, they can damage kidneys if there is a blockage for a long time. Some stones, if left untreated, can cause the kidney to stop working.
Diet changes recommended for heart conditions also often help prevent stones. A healthy diet with lots of fresh fruits and vegetables and less animal protein and salt can help avoid stones and other conditions. You can learn more from your health care provider or dietician. Keeping a normal weight can also help avoid diabetes and stones.
If a stone in the ureter does not pass in a reasonable time or is causing pain or infection, you will need endoscopic surgery to remove it.
You may get another stone even if you’ve had surgery, changed your diet or are taking medications. However, with the right diet and medical treatment, you can be less likely to get stones over and over again.
During treatment, your doctor may ask you to repeat investigations to see if your test results have improved. Your doctor will also check to see if you are having any side effects from your medications.

If you form stones often, you will need monitoring with X-rays and urine studies to be sure no new stones are forming. Your doctor will monitor you to make sure your medications and diet changes are working.
Yes. Any stone of any size needs medical attention. Larger asymptomatic stones need to be removed as they have a potential for trouble. Remember, “they may not be giving you any trouble but they would surely trouble your kidney.”

Stones smaller than 6 mm would pass out on their own, but they need a medical supervision to document their movement down the ureter and to confirm complete clearance.
Except uric acid stones, none of the stones can be dissolved by any form of medicine, let it be homeopathy, allopathy or ayurveda. Yes, one can pass a stone naturally when it is small, but for a stone to be able to pass out with the help of water and medicines, it has to be smaller than 6 -8 mm in size. Anything bigger than 8 mm has a less than 10% chance of passing out intact. Stones above 10mm in size should not be given medical treatment at all. It is very important to treat the stone when it is small and complications have not set in. The earlier the patient consults his urologist, the easier, cheaper, faster and less painful it is to remove his or her stone.

Yes, I have met a lot of patients who have gone to such places for removal of their stones. In fact, one of our patients was so convinced that his stone has been removed by magic that he refused to get himself investigated. There is no truth in this as far as we know and have seen. The proof is that these patients had to come to us for definitive treatment. What these people do is perform some sort of puja and give the patient a stone that has probably been picked up from the road. Because of the faith and some amount of coincidence, the patient does not get pain after that for some time (stone pain usually comes in episodes that may be spread over months or years). The patient realizes much later when he gets the next episode of pain that the stone is still there. Again, I would like to stress here that please get whatever form of treatment you have faith in but you must confirm complete stone removal by X-rays and sonography. Accept only those treatment options that can give an assured clearance in less than three months.

Beer does not help in dissolving kidney stones. In fact, beer is known to have excess oxalates and uric acid hence it can accelerate stone growth. There may be some diuretic (more urine production) effect of beer; but other fluids can also achieve this effect.

Friends, please do not have beer for stone clearance. Enjoy it if you please, but please do not use stone as an excuse.
No. Moderate amounts of Non-veg in diet are acceptable. All you need to do is reduce the amount and frequency of intake of red meat.
Indian food is salt rich. Excess salt in diet will increase the calcium in your urine. This tip is for people with high sodium intake and high urine calcium. Your doctor may advise you to avoid foods that have a lot of salt. The following foods are high in salt and should be eaten in moderation:
  • Papads, Aachars and chutneys

  • Extra table salt

  • Cheese (all types)

  • Most frozen foods and meats.

  • Canned soups and vegetables

  • Breads, rolls and baked goods

  • Salty snacks, like chips and pretzels

  • Bottled salad dressings and certain breakfast cereals

  • Pizza and lasagna

  • Canned and bottled sauces

  • Certain condiments, table salt and some spice blends

Yes. Urinary stone is an un-welcome friend for life! Once it forms it is likely to form again. The risk of recurrence of stone disease is there all through out your life hence your diet and fluid care is a permanent feature.

  1. A basic metabolic evaluation is necessary for every patient. This is a screening test for any etiology for stone disease.
  2. The person who is more likely to have recurrent stones may have one of these attributes. Has formed stones previously.
    • Have multiple stones.
    • Has stone in both his kidneys.
    • Family history of stone disease is positive.
    • Has formed stone at a young age.

This class of patients needs extra care. They need specialized investigations (Complete Metabolic evaluation) to rule out any predisposing cause. The investigations are in the form of few blood and urine tests. The urine is tested over 24 hours on more that two occasions.

Myth : Kidney stones are rare.

Fact : Kidney stones are one of the most common disorders of the urinary tract.

Myth : Only men get kidney stones.

Fact : Women get kidney stones too. Even children can get them.

Myth : Eating certain foods will cause kidney stones to develop.

Fact : Not usually.

Myth : Most kidney stones are formed from calcium, so calcium in the diet should be reduced.

Fact : That used to be what doctors thought, but no longer.

Myth : Most people with kidney stones have to undergo surgery.

Fact : Thankfully, this isn’t true any longer.

Myth : Once as person has kidney stones, there’s nothing that can be done to prevent future stones.

Fact : Most people can take action to reduce their risk of getting more stones.

Myth : If a person has kidney stones, he or she is more likely to have gallstones.

Fact : Not even close.

  1. Have adequate oral fluid intake. Aim to produce about 2500 ml urine in a day. You should drink small amount of fluids at frequent intervals. Any type of liquid is OK; water, sherbet, juice, coconut water.

  2. Avoid drinks like excessive tea & coffee, beer (Beer has a lot of oxalate and uric acid, it increases stone formation) & aerated drinks.

  3. It is not necessary to stop milk totally. A global restriction of diary products may increase risk of phosphatic stone formation in some patients. Also calcium is very vital for our bones & muscles. Patients can safely have milk & milk products equivalent to half a liter of milk every day (1000mg per day)

  4. It is NOT necessary to stop tomatoes, palak, brinjal, & all stuff having seeds. Seeds do not cause stones.

  5. Restrict mutton and red meat.

  6. Restrict table salt and foods containing excessive salt: papad, aachar, chutneys etc.

  7. Restrict the use of Pan & Gutka. This has an excess dose of lime in it. This high dose of calcium may lead to stone growth.

  8. Regular exercise is very important. Fast walking, jogging or skipping would be very good.

  9. Avoid constipation.

    • Increase fiber in your diet; fresh fruits, green leafy vegetables, salads.

    • May take some laxatives if necessary.

  10. Definitive dietary restrictions are necessary only after proper metabolic evaluation.

Scroll to Top